Spindle stopping method and apparatus for implementing same

ABSTRACT

A method of stopping spindles of drawtwisting or heavy ring twisting machines having a moving drive tape in contact with a rotating spindle whorl, comprising the steps of relieving the contact pressure between the tape and the spindle whorl by injecting compressed air into the converging space defined by the tape and the spindle whorl and braking each spindle by pressing a braking element against such spindle. There is also disclosed an apparatus for stopping a spindle of a multiple spindle tape drive having a moving tape in contact with a spindle whorl, which apparatus comprises tape lifting means for relieving the contact of the tape on the whorl, the tape lifting means comprising a nozzle injecting compressed air between the tape and the whorl in the direction of movement of the tape.

United States Patent Inventor Rudoll heal Bern, Switzerland App]. No.832,890 Filed June 131 1969 Patented Aug. 17, I971 Assignee RelterMachine Works Ltd.

- Winter-that, Switzerland Priority June 14, 1968 Switzerland SPINDLESTOPPING METHOD AND APPARATUS [56} References Cited] UNIT ED STATESPATENTS 3,224,180 12/1965 Graf 57/88 3,256,684 6/1966 Stahlecker et al.57/88.

Primary Examiner.lohn Petrakes Anomy-Weiner W Kleeman ABSTRACT: A methodof stopping spindles of drawtwisting or heavy ring twisting machineshaving a moving drive tape in contact with a rotating spindle whorl,comprising the steps of relieving the contact pressure between the tapeand the spindle whorl by injecting compressed air into the convergingspace defined by the tape and the spindle whorl and braking each spindleby pressing a braking element against such spindle. There is alsodisclosed an apparatus for stopping a spindle of a multiple spindle tapedrive having a moving tape in con tact with a spindle whorl, whichapparatus comprises tape |ifting means for relieving the contact of thetape on the whorl. the tape lifting means comprising a nozzle injectingcompressed air between the tape and the whorl in the direction ofmovement ofthe tape.

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SPINDLE STOPPING METHOD AND APPARATUS FOR IMPLEMENTING SAME The presentinvention .concems a new and improved method of stopping spindles ofdrawtwisting and heavy twisting machines provided with a drivearrangement driving a plurality of spindles, and an improved apparatusfor implementing the method.

In known spindle drive arrangements of conventional design a pluralityof spindles as a rule are driven by a tape surrounding four spindles.driven by a drive shaft. Stopping of the spindle iseffected by means ofbraking the spindle while the tape keeps running, so that friction heatis generated between spindle and tape, which can be dissipated to alimited extent only, as said heat depending upon the tape tension cancorrespond to twice and up to five times the value of the drive energyof the spindle. The increase of the friction heat generated by braking aspindle brought about by the increased package weight and spindle speedscauses excessive tape wear so that the tapes must be replacedperiodically within very short periods of life. Under extreme conditionsa tape might not withstand even one single braking cycle. For thisreason the elimination of multiple spindle tape drives and provision ofindividual spindle tape drives equipped with tape lifting brakes weretired. Such individual spindle tape drives are expensive compared tomultiple spindle tape drives. It also has been proposed to provided thespindles with a disengageably arranged whorl. This arrangement, however,has the disadvantage of considerable wear existing at the required whorlbearing. On the other hand, tape lifting brakes already have beenproposed which interrupt the contact between the tape and the spindlewhorl, apart from the aforementioned individual spindle drives. Suchtape lifting brakes, however, must be equipped with tension rolls takingup the tape path length difference between the drive position and thelifted position, if unduly high tensions are to be avoided. Furthermore,such tape lifting brakes also are relatively expensive if the liftingdevices are rolls or the like. If the cheaper lifting cams are chosen,friction against the tape again is generated, causing tape wear and heatgeneration also. It is the goal of the present invention to eliminatethese disadvantages and to provide a method as well as an apparatusensuring a long drive tape life, limiting design complication to aminimum, and suppressing any influence on the speed of spindles notsubject to the braking action. Also, friction heat still generatedbetween the whorl and drive tape is dissipated directly to thesurrounding air instead of being transferred to the spindle or to thedrive tape. The method according to the invention of stopping spindlesof drawtwisting or heavy ring twisting machines by means of relievingthe contact pressure of the drive tape against the spindle whorl ischaracterized in that an air cushion is formed between the drive tapeand the spindle whorl by means of injection of compressed air into theconverging space formed by the spindle whorl and the drive tape andbraking by pressing a braking element against the spindle.

The apparatus for stopping a spindle of a multiple spindle tape driveusing means of relieving the contact of the tape against the spindlewhorl is characterized in that the tape lifting element is formed by anozzle injecting compressed air in the direction of tape movementbetween the tape and the whorl.

The invention itself will be better understood from the followingdetailed description of a preferred embodiment thereof, taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view of the spindle drive elements of a portion ofa heavy ring twisting or drawtwisting machine constructed in accordancewith this invention;

FIG. 2 is a side elevational view, partly in section, taken along linesII-II of FIG. 1;

FIGS. 3 and 4 are axonometric views of two fonns of nozzles utilized inthe machine of FIG. 1;

FIG. 5 is a front elevational view of a flat nozzle;

FIG. 6 is a side sectional view of the nozzle of Figure 5, taken alonglines VI-VI;

FIG. 7 is an axonometric view showing a nozzle including a whorl;

FIG. 8 is a schematic plan view of a portion of the system supplying thenozzles with compressed air:

FIG. 9 is a schematic elevational view of a spindle with a nozzle andbrake; and,

FIGS. 10 and 11 are horizontal sectional views respectively showing twoforms of spindle brakes.

Referring first to FIGS. 1 and 2, a plurality of spindles 1 are mountedin the spindle rails 2. By means of a nozzle 3 compressed air isinjected into a converging space 4 between spindle whorls 5 (Fig. 2) andan oncoming drive tape 6, an air cushion building up between whorl 5 andtape 6, which reduces the contact pressure of the tape 6 on the whorl 5,and thus the torque transmitted, to such an extent, that spindle 1 canbe braked without application of a large braking force, by means of aspindle brake 7 of a type known as such, a valve 8' being activatedduring the braking action being provided for each nozzle. The compressedair is supplied by a network 8. A round nozzle 9 (FIG. 3) is suitablee.g. particularly for narrow drive tapes, a flat nozzle 10 (FIGS. 5 and6) or a nozzle 11 (FIG. 4) provided with a plurality of round exit holes12 for wide drive tapes. A nozzle 11' for very convex whorls W is shownin Fig. 7. Here one injector hole each is pointed an upwardly anddownwardly towards the plane E of the largest whorl circumference circleK. Thus a somewhat higher pressure builds up in this plane as the airstreams injected must be more deflected. Furthermore, a dual nozzlearrangement 13 (Fig. 8) is possible, allowing for a change of thedirection of the spindle rotation for producing an S or Z twist in theyarn, if a shiftable nozzle arrangement is not preferred. Also twoindependent nozzle systems can be used. A switching valve 15 insertedinto the network 14 is activated by a central control unit 16 while thedirection of spindle rotation is being reversed. Control of thecompressed air supply to the nozzles arranged at the spindles can becombined also with the braking device of the spindles, e.g. in amechanical spindle brake arrangement 17 a valve 19 of the nozzle 20 canbe activated by means of a brake foot pedal 18. If the brake 17 isreleased, valve 19 is closed again and the supply of compressed air isstopped (Fig. 9).

Activation of the brake shoe 21 by means of an electromagnet 22 combinedwith an electrovalve 23 for the supply of compressed air for nozzle 24activated by the same relays 21' is shown in Fig. II. Furthermore,pneumatic activation of brake shoes 25 by means of pressure ducts 26 canbe combined with a nozzle 29 connected to the same duct 27 via valve 28(Fig. 10).

Example: A four spindle tape drive arrangement, the spindles of whichare provided with a whorl of 62 mm. diameter, is driven by a drive tapeof 25 mm. width. The nozzle injecting compressed air is provided with aninjecting opening of 16 mm. width and 1 mm. height. It thus is a nozzleof the type shown in FIGS. 5 and 6. Using this arrangement at variousspindle speeds the following results were achieved:

As shown by experience a brake power of 360 W, correspond ing tostopping from 8,000 r.p.m. without using compressed air injection isfeasible. At 15,000 r.p.m. and at this maximum feasible brake power ofabout 360 W trouble free braking is possible if compressed air of about0.7 atmospheres above atmospheric pressure is injected.

Of course, another multiple spindle drive arrangement such as"e.g. atangential belt drive in which the belt is guided along the row ofspindles can be used instead of the four spindle tape drive mentionedabove. While there is shown and described present preferred emb'odimentsof the invention, it is to be distinctly understood plurality ofspindles, comprising the steps of relieving the contact pressure betweensaid tape and any given one of said spindle whorls by injectingcompressed air into the converging space defined by said tape and saidgiven spindle whorl desired to be braked, and braking said associatedspindle by pressing a braking element against said spindle, said drivetape remaining in contact with the remaining spindle whorls for drivingthe remaining associated spindles thereof even though said given spindlewhorl has been braked, so that anyone of said plurality of rotatingspindle whorls can be braked independently of and without stopping thedrive tape from continuing to drive the remaining spindle whorls.

, 2. A method as defined in claim 1, wherein said compressed air isinjected into said converging space in the direction of movement of saidtape.

3. A method as defined in claim 1, wherein said braking and saidinjection of compressed air occur simultaneously.

4. A method of stopping spindles of drawtwisting or heavy ring twistingmachines having a moving drive tape in contact with a rotating spindlewhorl, comprising relieving the contact pressure between said tape andsaid spindle whorl by injecting compressed air into the converging spacedefined by said tape and said spindle whorl and braking said spindle bypressing a braking element against said spindle, a single source ofcompressed air being used both for said injection of compressed air andfor pressing said braking element against said spindle.

5. An apparatus for stopping a spindle of a multiple spindle tape drivehaving a moving tape in contact with each spindle whorl of a pluralityof spindles, comprising tape lifting means for relieving the contact ofsaid tape with each said whorl of said plurality of spindles, said tapelifting means comprising for each spindle at least one nozzle forselectively injecting compressed air between said tape and any given oneof said whorls in the direction of movement of said tape, to therebyrelieve the contact of said tape with said given whorl while the tapestill remains in contact with the remaining whorls for driving theremaining associated spindles thereof even though said given whorl hasbeen placed out of contact with the moving tape.

6. An apparatus for stopping a spindle of a multiple spindle tape drivehaving a moving tape in contact with a spindle whorl, comprising tapelifting means for relieving the contact of said tape in said whorl, saidtape lifting means comprising a nozzle injecting compressed air betweensaid tape and said whorl in the direction of movement of said tape, asupply of compressed air for said nozzle, and braking means for eachsaid spindle, said supply of compressed air and said braking means beingconnected to a single control means.

7. An apparatus as defined in claim 6, wherein said supply of compressedair and said braking means for said spindle are activated byelectromagnets.

8. An apparatus as defined in claim 6, wherein said braking means forsaid spindle is pneumatically activated, said source of compressed airand said braking means beingconnected to a common pressure source bymeans of a common valve.

9. An apparatus as defined in claim 5, wherein each said spindle has twoof said nozzles, said nozzles operating alternativeij' depending uponthe direction of rotation of said spindle. l An apparatus for stopping aspindle of a multiple spindle tape drive having a moving tape in contactwith a spindle whorl, comprising tape lifting means for relieving thecontact of said tape on said whorl, said tape lifting means comprising anozzle injecting compressed air between said tape and said whorl in thedirection of movement of said tape, each said spindle having two of saidnozzles, said nozzles operating alternatively depending upon thedirection or rotation of said spindle, said alternative actuation ofsaid nozzles being effected by means of a switching valve activated by acontrol means.

11. An apparatus for stopping a spindle of a multiple spindle tape drivehaving a moving tape in contact with a spindle whorl, comprising tapelifting means for relieving the contact of said tape on said whorl, saidtape lifting means comprising a nozzle injecting compressed air betweensaid tape and said whorl in the direction of movement of said tape, eachsaid spindle having two of said nozzles, said nozzles operatingalternatively depending upon the direction of rotation of said spindle,braking means for each said spindle, said nozzle and said braking meansfor said spindle being jointly actuated by a common actuating means.

12. An apparatus as defined in claim 5, wherein said nozzle comprises aflat nozzle.

13. An apparatus as defined in claim 12, wherein said flat nozzlecomprises a plurality of injector openings for said compressed air.

14. An apparatus as defined in claim 13, wherein said injector openingsare mutually inclined so that a converging stream of compressed air isformed meeting said whorl at its largest diameter.

1. A method of stopping individual spindles of drawtwisting or heavyring twisting machines having a single-moving drive tape in contact witha plurality of rotating spindle whorls of a plurality of spindles,comprising the steps of relieving the contact pressure between said tapeand any given one of said spindle whorls by injecting compressed airinto the converging space defined by said tape and said given spindlewhorl desired to be braked, and braking said associated spindle bypressing a braking element against said spindle, said drive taperemaining in contact with the remaining spindle whorls for driving theremaining associated spindles thereof even though said given spindlewhorl has been braked, so that anyone of said plurality of rotatingspindle whorls can be braked independently of and without stopping thedrive tape from continuing to drive the remaining spindle whorls.
 2. Amethod as defined in claim 1, wherein said compressed air is injectedinto said converging space in the direction of movement of said tape. 3.A method as defined in claim 1, wherein said braking and said injectionof compressed air occur simultaneously.
 4. A method of stopping spindlesof drawtwisting or heavy ring twisting machines having a moving drivetape in contact with a rotating spindle whorl, comprising relieving thecontact pressure between said tape and said spindle whorl by injectingcompressed air into the converging space defined by said tape and saidspindle whorl and braking said spindle by pressing a braking elementagainst said spindle, a single source of compressed air being used bothfor said injection of compressed air and for pressing said brakingelement against said spindle.
 5. An apparatus for stopping a spindle ofa multiple spindle tApe drive having a moving tape in contact with eachspindle whorl of a plurality of spindles, comprising tape lifting meansfor relieving the contact of said tape with each said whorl of saidplurality of spindles, said tape lifting means comprising for eachspindle at least one nozzle for selectively injecting compressed airbetween said tape and any given one of said whorls in the direction ofmovement of said tape, to thereby relieve the contact of said tape withsaid given whorl while the tape still remains in contact with theremaining whorls for driving the remaining associated spindles thereofeven though said given whorl has been placed out of contact with themoving tape.
 6. An apparatus for stopping a spindle of a multiplespindle tape drive having a moving tape in contact with a spindle whorl,comprising tape lifting means for relieving the contact of said tape insaid whorl, said tape lifting means comprising a nozzle injectingcompressed air between said tape and said whorl in the direction ofmovement of said tape, a supply of compressed air for said nozzle, andbraking means for each said spindle, said supply of compressed air andsaid braking means being connected to a single control means.
 7. Anapparatus as defined in claim 6, wherein said supply of compressed airand said braking means for said spindle are activated by electromagnets.8. An apparatus as defined in claim 6, wherein said braking means forsaid spindle is pneumatically activated, said source of compressed airand said braking means being connected to a common pressure source bymeans of a common valve.
 9. An apparatus as defined in claim 5, whereineach said spindle has two of said nozzles, said nozzles operatingalternatively depending upon the direction of rotation of said spindle.10. An apparatus for stopping a spindle of a multiple spindle tape drivehaving a moving tape in contact with a spindle whorl, comprising tapelifting means for relieving the contact of said tape on said whorl, saidtape lifting means comprising a nozzle injecting compressed air betweensaid tape and said whorl in the direction of movement of said tape, eachsaid spindle having two of said nozzles, said nozzles operatingalternatively depending upon the direction or rotation of said spindle,said alternative actuation of said nozzles being effected by means of aswitching valve activated by a control means.
 11. An apparatus forstopping a spindle of a multiple spindle tape drive having a moving tapein contact with a spindle whorl, comprising tape lifting means forrelieving the contact of said tape on said whorl, said tape liftingmeans comprising a nozzle injecting compressed air between said tape andsaid whorl in the direction of movement of said tape, each said spindlehaving two of said nozzles, said nozzles operating alternativelydepending upon the direction of rotation of said spindle, braking meansfor each said spindle, said nozzle and said braking means for saidspindle being jointly actuated by a common actuating means.
 12. Anapparatus as defined in claim 5, wherein said nozzle comprises a flatnozzle.
 13. An apparatus as defined in claim 12, wherein said flatnozzle comprises a plurality of injector openings for said compressedair.
 14. An apparatus as defined in claim 13, wherein said injectoropenings are mutually inclined so that a converging stream of compressedair is formed meeting said whorl at its largest diameter.